A unique neurological disease initially identified among the Chamorro people of Guam by Kurland and Mulder (1954) is characterized by a combination of symptoms including stooped posture, a blank expressionless face, dementia, slow shuffling movement, a resting tremor that stops upon deliberate action, slow movements, and muscle atrophy that results in muscles dipping down in the hand. In some clinical manifestations, patients have clinical symptoms indistinguishable from amyotrophic lateral sclerosis (ALS). Other patients have Parkinsonism features combined with dementia (Parkinsonism Dementia Complex, PDC). In still others, only dementia is observed. Some patients also have both ALS and PDC. Neuropathologically, all clinical forms of the disease result in a specific feature, neurofibrillary tangles, found in the cortex and in the spinal cord. Because the disease has aspects that resemble amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD) and Alzheimer's disease (AD), this disease is known as amyotrophic lateral sclerosis-Parkinsonism dementia complex of Guam (ALS-PDC) and is also known as lytico-bodig.